Aqueous adhesive dispersions and the use thereof in the production of multi-layered paper

Abstract

An aqueous adhesive dispersion comprising an adhesive polymer in dispersed form, an anionic or cationic polyelectrolyte, and optionally at least one polyalkylene glycol having a molar mass of 200 to 100,000 g/mol, and other additives; and a process for producing multilayered paper or a material using the aqueous adhesive dispersion.

What is claimed is:  
     
       1. An aqueous adhesive dispersion consisting essentially of 
       A) 0.1-6 wt. %, relative to the total weight of the dispersion, of an adhesive polymer in dispersed form,  
       B) 0.1-10 parts by weight, relative to 100 parts by weight of component A), of an anionic or cationic polymeric, water soluble or water-swellable polyolectrolyte, and  
       C) 0-50 parts by weight, relative to 100 parts by weight of component A), of at least one polyalkylene glycol having a molar mass ranging from 200 to 100,000 g/mol, and optionally other additives,  
       wherein at least one water-soluble or water-swellable cationic or anionic synthetic homo- or copolymer of monoethylenically unsaturated monomers having acid groups, which at least partially are present as salts or as esters or amides of dialkylaminoalkylalcohols or -amines in protonated or quaternized form, and optionally other monoethylenically unsaturated monomers, Mannich bases of polymers containing acrylamide, polyvinylamines, polyamines, and polyalkylenepolyamines, having molar masses of from 450 to 100,000 g/mol, melamine-formaldehyde condensation products, urea-formaldehyde condensation products in anionic and cationic modification, or polyamidoamine-epichlorohydrin resins or mixtures thereof are used as component B).  
     
     
       2. The adhesive dispersion according to  claim 1 , wherein the adhesive dispersion contains 2-6 wt.-% of component A), relative to the total weight of the dispersion. 
     
     
       3. The adhesive dispersion according to  claim 1 , wherein the adhesive dispersion contains 0.1-30 parts by weight, relative to 100 parts by weight of component A), of at least one polyalkylene glycol. 
     
     
       4. The adhesive dispersion according to  claim 1 , wherein at least one natural or synthetic polymer is used as component A). 
     
     
       5. The adhesive dispersion according to  claim 4 , wherein native starch, modified starch, cellulose ethers, guar meal, alginates, proteins, and/or polyvinyl alcohol are used as component A). 
     
     
       6. The adhesive dispersion according to  claim 5 , wherein cationic or anionic starch is employed as component A). 
     
     
       7. The adhesive dispersion according to  claim 1 , wherein at least one polyethylene glycol is used as component C). 
     
     
       8. The adhesive dispersion according to  claim 1 , wherein component B) does not act as a flocculant below the gelatinization temperature of component A). 
     
     
       9. The adhesive dispersion according to  claim 1 , wherein acrylic acid, methacrylic acid, maleic acid, itaconic acid, crotonic acid, and vinylsulfonic acid, (meth)acrylamidoalkanesulfonic acids, 2-sulfoethyl methacrylate, styrenesulfonic acid, vinylphosphonic acid, and/or styrenephosphonic acid, as well as their alkali or ammonium salts are present as recurring units in the anionic homo- or copolymers as monoethylenically unsaturated monomers containing acid groups, and (meth)acrylic acid esters with dialkylaminoalkylalcohols or (meth)acrylic acid amides with dialkylaminoalkylamines in protonated or quaternized form are present as recurring units in the cationic homo- or copolymers. 
     
     
       10. The adhesive dispersion according to  claim 1 , wherein component A) and component B) exhibit dissimilar ionogenicity. 
     
     
       11. A process for producing multilayered paper or a sheet material comprising paper material and formed of at least 2 paper webs, by coating an aqueous adhesive dispersion onto at least one paper web in wet condition, compressing and drying the combined paper webs, wherein a dispersion according to  claim 1  is used as adhesive dispersion. 
     
     
       12. The process according to  claim 11 , wherein the adhesive dispersion is sprayed onto at least one paper web. 
     
     
       13. The adhesive dispersion according to  claim 4  wherein said at least one natural or synthetic polymer is selected of the group consisting of a polysaccharide, a modified polysaccharide, a protein, a polyvinyl alcohol, and mixtures thereof. 
     
     
       14. The adhesive dispersion according to  claim 3 , wherein the adhesive dispersion contain 0.1 to 20 parts by weight relative to 100 parts by weight of component A, of at least one polyalkylene glycol. 
     
     
       15. The adhesive dispersion according to  claim 1 , wherein the weight ratio of component A) to component B) is from 4:1 to 25:1. 
     
     
       16. The adhesive dispersion according to  claim 15 , wherein the weight ratio of component A) to component B) is from 10:1 to 25:1. 
     
     
       17. The adhesive dispersion according to  claim 16 , wherein the weight ratio of component A) to component B) is from 14:1 to 20:1. 
     
     
       18. The adhesive dispersion according to  claim 1 , wherein 2-acrylamido-2-methylpropanesulfonic acid is used as component B).